Curaçao opens up in two directions from Willemstad. Bandabou to the west is the stronger full-day trip, combining the island's best cove beaches with Christoffel and Shete Boka national parks. Leave early, particularly if you plan to hike.
Bandariba to the east is easier to explore in a half-day. Fort Beekenburg, the Tugboat wreck, and Director's Bay form a compact cluster around Caracas Bay; Den Paradera and the ostrich farm can extend the loop into the countryside.
Klein Curaçao is the full-day boat option: a long white beach, clear water, an abandoned lighthouse, and wrecks on an otherwise uninhabited island. Compare boats and included facilities carefully, and prepare for a rough outward crossing.
A rental car is the practical choice for either road trip. Public transport reaches some settlements but does not make a flexible sightseeing circuit possible.